Yeah, but then I procrastinated, and now the channel's gone, so what 'cha gonna do.

I agree. Either that or AbaRanger.

For opening it's a toss-up between Denjiman and Dairanger for me. I think Denjiman has a good catchy beat:

https://www.youtube.com/watch?v=C0sfYmhZwdk

But Dairanger does have the whole "TENSHIN DA! WO-WO-WO-WO!" thing going for it:

https://www.youtube.com/watch?v=U8GQhvI2-N8

That said, there is no bigger Sentai earworm than Kauranger's ending theme:

https://www.youtube.com/watch?v=fokxJLHwATo

GoGo-V and Megaranger.

ToQger is my new favourite, and I pretty much listened to it on repeat when it was first leaked. Love it, but it would be unfair to call it my catchiest when I've just watched one episode, so it gets left out of the poll for now.

To be honest I've found every theme Shinkenger onwards to be crazy catchy. According to my ears, they truly, truly have not failed even once. Shinkenger, Goseiger, Gokaiger, Go-busters, Kyoryuger and ToQger were all terrific. If we leave ToQger out, I'll go with Kyoryuger, and I don't even watch the show.

I really like Carranger's theme. It's been stuck in my head for a while.

Off the top of my head: Kyoryuger, Kakuranger, Tokkyuger, and Gokaiger's theme songs are all very catchy and memorable I know i've found myself humming the kakuranger theme on more then one occasion.

Other notable mentions: The 2nd Gobusters Opening, and AbaRanger's opening…Endoh Masaki 'nuff said.

If we're to include character themes and action theme songs there's: DekaMaster Never Stop, KyoryuGold Iza! The Radiant Brave, Kyoryu Silver!, Boost Up! Beat Buster and Braigaigoh's theme songs are all great.

My pick is Dekaranger, both the Opening and end.
http://www.youtube.com/watch?v=vQKrBlIXPO0

http://www.youtube.com/watch?v=UR3KoS96qjQ

Kyoryuger, Battle Fever J, Magiranger, Gokaiger, and Abaranger are some of my favorites. Also Bioman, Dairanger, Gaoranger, and Ohranger's openings too.

Pffft. Almost. Son I had the whole thing memorized 3 times over by the time ep started.